The invention relates to a circuit for detecting pulses in an electric input signal, superposed on a specific reference level. The circuit has an input terminal for receiving the electric input signal, and to a video recorder comprising the circuit. The use in a video recorder is intended in particular for reading CTL pulses recorded on a separate track which extends at the edge of and in the longitudinal direction of the magnetic record carrier over this record carrier.
These CTL pulses are read in order to ensure that the video heads correctly follow the video tracks which extend obliquely on the magnetic tape. Moreover, these pulses can be read in order to be used in the VISS or VASS option of VHS video recorders (VISS and VASS meaning VHS index/address search system). Reading the CTL pulses sometime presents problems because these pulses may have different amplitudes and pulse widths at different tape speeds.
It is an object of the invention to provide a pulse-detection circuit which is capable of correctly detecting pulses whose amplitude and width vary as function of time.